If individuals lose weight to acquire a BMI of 25, do they, on average, acquire the risk factor profile of individuals who have over a period of time maintained a BMI of 25? Currently there is little evidence on which to base a response to this question. The beneficial effects of weight loss on risk factors for diabetes and cardiovascular disease (CVD) are well documented, however, the effect of a history of higher weight on risk factors is unclear. It seems logical that individuals might pay a price for past obesity, such that individuals currently at the same weight would have different risk profiles depending on their weight history. Nevertheless, it is not clear if individuals who were previously heavier (i.e., lost weight) retain a higher risk compared to individuals of similar weight with a history of weight maintenance. The research proposed here will: 1. Determine whether individuals who lose weight attain different mean levels of risk factors for CVD compared to individuals with the same BMI (at the end of the interval) who maintained their weight. 2. Determine whether CVD risk factors in weight maintainers and weight losers (as defined in Aim 1) are different after an additional year in which both groups maintained weight. 3. Establish whether physical activity, physical fitness, and dieting contribute to differences between weight maintainers and weight losers (as defined in Aims 1 and 2). We will accomplish these aims through analysis of extant data from the Aerobics Center Longitudinal Study (ACLS). Risk factors examined will include fasting glucose, systolic and diastolic blood pressure, total cholesterol, LDL cholesterol, HDL cholesterol, and triglycerides, The repeated measures of body weight and CVD risk factors assessed in the ACLS cohort make it a rich source for these analyses, This research will have strong implications for understanding and clarifying the possible benefits of weight loss, The proposed project is responsive to PA-03-015.